Based on completed studies that show (1) numerous isolates of enterovirus 70 (E70) and Coxsackie-virus A24 (CA24) are sensitive to IF and induce little if any IF, depending on the strain, (2) these viruses are adaptable to cell cultures of human, mouse, rabbit, hamsters and monkey origin, and (3) they are inhibited in their growth by temperatures beginning slightly above 37 degrees, the following research program is proposed: a. Studies will be continued to adapt the most promising E70 and Coxsackie A24 isolates to grow to high titer in cell and eye organ cultures originating from mice, rabbits, hamsters, and monkeys. b. Attempts to infect the eyes and central nervous system of immature species of mice, rabbits, hamsters, and monkeys with virus isolates that grew well in cell or organ cultures of each particular species will be continued and broadened. (If, in some cases, this is not possible, direct inoculation of the eyes and CNS of immature animals by high titered virus suspensions will be performed, and at least 10 blind passages made.) c. If a suitable animal model system is established, the effect of IF, IF inducers, specific hyperimmune antibody, and temperature elevation on patholgenesis of this eye disease will be studied and explored in detail to determine optimal conditions for possible application of these defense factors for control of epidemics of individual cases of the disease in humans. d. The relationships between antibody formation, virus replication and the pathogenesis of this infection in man using human specimens, including tears, eye scrapings, and acute and convalescent serum (a number of thse specimens are present in the laboratory and more are expected) will be examined. e. A serological study designed to determine the susceptibility of the Gulf Coast population to these viruses and to determine if these viruses have been active in this country in the past will be conducted.